The present invention relates to the field of conveyor system roller beds, and in particular, to a powered roller bed with multiple rollers on each row.
Conveyor system roller beds typically comprise a series of rollers driven by a chain to move articles traveling thereon from one location to another. Rollers in such systems are typically supported on a frame and positioned transverse to the direction of travel. A typical roller bed also has side walls or bumpers to help maintain articles, such as skids, packages, luggage, automobile parts, etc., on the bed as they travel thereon.
In prior roller bed designs, sets of spaced apart rollers are typically daisy-chained together so that multiple rollers can be driven by a single motor. While each roller in such systems can be provided with its own gears, the gears are chained together so that a single motor can be used to drive the chain, which in turn drives the rollers. Belts on fluted rollers can also be used.
A disadvantage of such systems, however, is that if one motor breaks down, the entire section of the conveyor system driven by that motor shuts down as well. Such rollers are also difficult to replace because the chain must be disengaged to access the rollers and often have covers that must be removed. Such rollers are also not capable of being independently controlled and operated, thereby making it more difficult to control the articles traveling on the bed.
In view of the drawbacks of prior conveyor system roller beds of the kind described above, a need has developed for an improved roller bed design. The present invention solves the above problems by providing rollers that are independently controlled and operated, and by providing a plurality of rollers on each row (or roller axis) of the bed. The present invention also contemplates rollers that can be easily installed and removed without the need of tools, so that downtime can be minimized.
The present invention represents an improvement over previous conveyor system roller bed designs, and in particular, designs incorporating rollers that are daisy-chained together and driven by a single motor. Like previous roller bed designs, the present invention comprises multiple rollers mounted transverse to the direction of travel, but unlike previous designs, the present invention comprises rollers with self-contained motors that allow each roller to be independently controlled and operated, as well as a plurality of rollers on each row of rollers, i.e., two or more rollers extending end-to-end on each row, which are capable of being easily replaced.
In one aspect, the present invention comprises using self-powered rollers that have electromagnetic motors with an inverted stator and rotor design, wherein a hollow cylindrical roller can rotate about a fixed shaft. Each roller preferably has high torque capacity and is provided with its own gear box, clutch, brake, control unit, etc. The rollers are also preferably capable of being connected to a central control unit to allow each one to be independently controlled and operated. Using self-powered rollers eliminates the need for certain components found in previous designs, including chains and belts, line shafts and other drive elements, as well as elaborate safety guards to cover the moving parts.
In another aspect, the present invention comprises more than one self-powered roller on each row, i.e., two or more rollers preferably extending (end-to-end) along the same axis transverse to the direction of travel. In this respect, the present invention is preferably adapted so that on any given row, one shaft of one roller can be mounted to the frame on one side of the bed, and another shaft of another roller can be mounted to the frame on the other side of the bed, wherein the rollers can be mounted end-to-end along the same axis. In the preferred arrangement, there are two rollers on each row or axis, although more than two rollers can be used. The rollers also do not have to extend along the same axis.
Providing more than one roller on each row has certain advantages not offered by a single roller design. For example, providing multiple rollers on each row allows the speed of the articles traveling thereon to be adjusted with more accuracy and flexibility. In this respect, a roller bed can effectively be split into two or more roller beds running side by side, which can be beneficial in situations where one roller bed is connected to two roller beds extending in different directions. That is, by effectively splitting the roller bed in this manner, articles on one side of the bed can be driven at one speed (prior to entering the first connected bed), and articles on the other side of the bed can be driven at another speed (prior to entering the second connected bed), such that by the time the articles reach their destinations, the articles are traveling at the appropriate speedsxe2x80x94the same speed as the connected beds.
Providing rollers on each row moving at different speeds can also be advantageous when used in connection with conveyor runs that have curved paths, wherein the travel distance along the outside of the curve is greater than that along the inside. In this respect, the rollers on the outside can be driven faster than those on the inside, to accommodate the greater travel distance along the outside, which can be particularly advantageous in helping to control small articles around a turn.
In another aspect of the invention, each roller is preferably adapted to be attached to the conveyer frame in a manner that allows them to be easily installed and/or removed by hand (without the use of tools), which can significantly reduce downtime in the event of a broken roller. For example, the present invention contemplates using two slotted brackets per roller that can be secured to the frame to support each roller, wherein each roller""s shaft can be inserted into the slots within the brackets and connected to the frame. In this way, to remove a roller from the frame, the roller simply has to be lifted up and out of the brackets, and to install a roller, the roller simply has to be lowered into the brackets. No screws, nuts or bolts are otherwise required to maintain the rollers securely on the frame.
Although the preferred embodiment of the present invention has been disclosed above, the present invention contemplates that other embodiments, such as those not specifically mentioned herein, which provide similar functions, are also within the contemplation of the present invention.